CVE-2025-46384 is a high-severity vulnerability classified under CWE-434, which pertains to the unrestricted upload of files with dangerous types. This vulnerability affects Emby Media Server version 4.8 running on Windows platforms. The core issue lies in the application's failure to properly restrict or validate the types of files that users can upload. As a result, an attacker with at least low-level privileges (PR:L) can upload malicious files without requiring user interaction (UI:N). The vulnerability has a CVSS 3.1 base score of 8.8, indicating a high impact on confidentiality, integrity, and availability. The attack vector is network-based (AV:N), meaning exploitation can occur remotely over the network. The vulnerability scope is unchanged (S:U), so the impact is confined to the vulnerable component. Successful exploitation could allow an attacker to execute arbitrary code, escalate privileges, or disrupt service by uploading malicious executables or scripts disguised as media or other file types. Since the vulnerability does not require user interaction and has low attack complexity (AC:L), it is relatively straightforward for an authenticated attacker to exploit. No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that organizations using Emby 4.8 on Windows should prioritize mitigation and monitoring to prevent potential exploitation.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on Emby Media Server for internal or external media streaming services. Confidentiality could be compromised if attackers upload files that enable them to access sensitive media content or internal network resources. Integrity is at risk because malicious files could alter or replace legitimate media files, potentially spreading malware or misinformation. Availability could be disrupted if attackers upload files that cause the server to crash or consume excessive resources. Organizations in sectors such as media, education, hospitality, and corporate environments that use Emby for content distribution or internal communications are particularly vulnerable. Additionally, since the vulnerability requires only low privileges, insider threats or compromised user accounts could be leveraged to exploit this flaw. The lack of user interaction requirement further increases risk, as automated attacks or scripts could be used to exploit the vulnerability at scale.

To mitigate this vulnerability effectively, European organizations should: 1) Immediately restrict file upload permissions to trusted users only and enforce strict authentication and authorization controls. 2) Implement file type validation and filtering on the server side to allow only safe and expected file formats, rejecting any executable or script files. 3) Monitor upload directories and logs for unusual or unauthorized file uploads, employing automated detection tools to flag suspicious activity. 4) Isolate the Emby server in a segmented network zone with limited access to critical infrastructure to reduce lateral movement risk. 5) Apply the principle of least privilege to the Emby service account and related user accounts to minimize exploitation potential. 6) Regularly update and patch the Emby software once a vendor fix is released. 7) Consider deploying web application firewalls (WAFs) or intrusion prevention systems (IPS) that can detect and block malicious file uploads. 8) Educate users about the risks of uploading untrusted files and enforce organizational policies accordingly.